Need help with external config

I have ComCast Business Class with a static ip address. I am allowed 1 domain name with them and want to make that my main portal. This part is working as www.inwoon.net.
I want to add the subdomains ns1 and ns2 respectively so I can let the user set their DNS to ns1.inwoon.net and ns2.inwoon.net.
Help I am stuck on how to set my Master DNS record at ComCast to pass through all requests to the web sites registered with me.
I know it is fairly easy but the DNS manual is scary.
Any help is greatly appreciated.

If you're hosting your own dns server and using your primary domain also as a name server then you normally need to just make glue records with it's registrar.

First you need to create the two ns records in ispconfig.

I'd also use the wizard to make the other records.

Then you need to make glue records with the registrar for the two ns records pointing them to your ip. That way all requests to ns go straight to your server. Be aware that some registrars wont allow the same ip address to be used twice on records.

Its a bit long winded to explain the details here. Search on this site for 'run your own name server ispconfig'